The present invention relates to an arrangement for optical image processing by spatial filtering.
As is well known, optical computers can perform, for instance, Fourier transformations at the speed of light by parallel information processing. In one known embodiment of optical iamge processing, a multilayer structure with a liquid crystal is provided as an absorption filter with two-dimensionally controlled absorption. Since in this filter, the location dependent absorption must be written in optically, the processing of image information which is present electronically, requires an additional transformation. In addition, image processing with coherent light is not possible in this embodiment since phase errors are not precluded in this multilayer structure (See U.S. Pat. No. 4,351,589).